Factoring Dun Factor

Factor – one of two or more numbers or expressions that are multiplied to obtain a given product.

Dun horses are often mistaken for buckskin horses and visa versa.  There is a clear difference though, and being that all five of my horses are dun factored horses, I will show you just what makes a dun horse dun.

All three of these horses can be considered a dun horse.  Yes, there are three very different variations one being a grulla, a dark bay dun and a lighter bay dun or “coyote dun.”  First off we’ll start with a grulla pronounced grew-ya.  A little bit of Spanish language in highschool will teach you that when you have two L’s right next to eachother they say “ya,” i.e. tortilla (tor-T-ya).  Please, in the name of all things good, do not pronounce grulla, “grew-la.”  It’s tacky and obscene to a dun lover like myself.  I actually got in an argument about it with a supposed “mustang-know-it-all.”  I’m normally very quiet in person but it annoyed me no end to hear her say grew-la and when I gently and informatively corrected her, she said she knew how to pronounce it because her husband was a BLM mustang inspector… Big deal lady, you sure wouldn’t know a Spanish word if it jumped up and bit you in the butt.

This is a very dappled (so my horses thrive on being obese), light grulla mare.  I like to call her a latte grulla but in order to not confuse, most people would call her a silver grulla because she is so light in color.

Her face has a dark mask up the bridge of her nose which is a definite dun factor marking.  This marking shows up most of the time in dun factored horses.  The next thing you’ll notice is her wildly bi-colored mane.  The light frosted color is a dun factor marking though this does not show up in all dun horses, and some lines have it more prevalent than others.  I have another mare who is this mare’s half sister (same sire) that also has the beautiful bi-coloring.  All my others do not have it, but that doesn’t mean they aren’t dun.  Next you’ll see her dark dorsal stripe.  A dun horse MUST have a dorsal stripe but all horses who have a dorsal stripe are not dun. 

Notice that this dorsal stripe is very well defined.  There is no haziness to the lines, it is crisp and dark… year round.  You can always see this stripe in her winter woolies and in the summer, it never fades.  Some horses will have what you might think is a dorsal stripe when it is actually countershading.  Countershading can show up in most all colors but the stripe will fade in the winter and it’s edges are not crisp.

A dun factored horse’s dorsal stripe will also continue down the tail with light guard hairs on either side in the beginning of the tail.  A countershaded horse’s dorsal will stop abruptly at the tail head.

The other interesting thing about a grulla is this, it is essentially a black horse.  You take the black coloring, put a layer of dun factor over it, and you get a grulla.  I won’t go into all the icky genetics details, even if I could, I wouldn’t because it can be quite complicated.

A grulla horse can come in multiple shades.  Just like a human’s brown hair can be light, dark or medium.  Here are my two grullas for a comparison.  The darker mare in front is a more common grulla color, she can almost look purple some times of the year and gets a dark charcoal color in the winter.  Another grulla shade would trick most people in to thinking it was black.  I know a few Kigers who are a very black color, but you will notice that they have fawn coloring inside their ears, this is a dead giveaway to the dun factor at work.

The darker grulla mare has a very dark face mask, her ears are rimmed in black, and there’s the fawn coloring inside.

Her dorsal also continues down the very beginning of her tail, definitely not as striking as the lighter grulla mare, but still there.

They also have dark tips on the back of their ears and see that little smudge of darker hair a little down on the back of the ear?  That is considered an ear bar.

Normally on a grulla, the leg barring as you see here is very distinct.  One of the exceptions is the darker grulla mare, hers is nothing near as striking.  In fact you cannot see the very slight barring in the winter where you can see this lighter grulla mare’s very easily.

The lighter mare also displays some eye makeup as you’ll notice black smudges that go upward from the corners of her eyes.  She also displays some bi-coloring in her forelock though not as loud as that in her mane.

This mare is a prime example of a bay dun.  She is a lighter yellow color with an orange hue.  Essentially she is a bay horse with a slather of dun genetics which dilute her coloring to this lighter yellow.  Some people would consider her to be a buckskin, a buckskin though, is a yellow horse with a black mane and tail that does not have any striping (though can have the countershading as mentioned before).  A buckskin’s bay base color is diluted by a “cream gene,” not the dun factor gene.  And the buckskin is normally a more pure yellow color, without the orange hue.

Her leg barring is made up of black hairs and still has a good amount of showiness to it.

Her dorsal stripe is pronounced and runs it’s course from wither to tail…

…And on down through the tail with the lighter guard hairs on either side (never mind the wrinkly butt, like I said, being obese agrees with my horses).

Her lovely eye, just had to share.  Notice she doesn’t have the eye makeup?  That doesn’t mean she’s not a dun though. 

She does have something that the res to the horses don’t and that is a pair of jack stripes on her shoulders coming down from her withers.  Some horse’s jack stripes are more pronounced and of course your burros and donkeys are very pronounced, but nonetheless, they’re here on this mare.

This is my very handsome gelding, the only man in the bunch.  He is a very dark bay dun and could be thought of as bay by a lot of eyes who are not used to the dun coloring.

He has a very black mane and tail, a very slight facial mask that is almost indistinct but…

He has a very pronounced dorsal stripe that continues down to the very very beginning of his tail with just a handful of lighter guard hairs on either side, (unfortunately after all my shooting I realize I didn’t get a pic of it, but they are there!)

He does have a dark shoulder patch, not to be confused with the jack stripes.  This is a large dark area that can be on the withers and on the neck. 

He also has some barring even though it is not as loud as the others.

Last but not least, I have a red dun mare, the one on the far left.  She is the half sister I mentioned to the lighter grulla.

See the family resemblence in the mane (also notice the red ear tips)?  They get that from their sire who also has the same wild bi-coloring. 

The neat thing is it is natural and they don’t have to spend big bucks in a fancy salon to get it done like so many women today.

She has the eye makeup that goes up from the corner of her eyes.

More of mottled barring unlike the definite stripes of the others.

And her dorsal, though thin is still defined and goes down in to her tail.  Notice that there are black hairs in her tail?  I once had someone tell me that she is not a red dun because she has black in her tail.  That is very false because a red dun is essentially a chestnut horse with a slather of dun factor over it.  How many chestnuts do you know that have black in the base of their tails?  I know quite a few, so why can’t a red dun have black in their tails?  They can and they do.  The thing about a red dun is that their dun factor markings are red, that includes the facial masks, the ear bars/tips, the dorsals (though a lot of bay duns have red dorsals), and their leg barring is redish orange or a dark brown and not black.

I hope you learned something new today now go forth and say “grew-ya” not “grew-la,” and make me proud!

About mudranch

I live in the country, I love to take photos, I'm a shepherdess, I adore my husband and daughter, I walk in the will of Christ.

Posted on August 21, 2008, in Horses, Kiger Mustangs. Bookmark the permalink. 14 Comments.

  1. Very beautiful horses and I can see you have a strong preference for the “grew-ya” color. I can honestly say I have never enjoyed looking at legs and butts as much as with your tour today, thanks……….

  2. Very interesting and extremely informative. We specialize in cream dilute (buckskin, palomino, etc) paso finos, so I’m always on the look-out for explanations and examples of genetics at work. Yours has to be one of, if not the best, explanation of the dun gene I’ve seen. Excellent!

  3. Mary – Glad you enjoyed the view! 🙂

    Pamela – Thank you so much for such a kind compliment! Glad you enjoyed it too… I sure don’t know as much about it as a lot of folks but I think I’ve got the basics enough to share what I know.

  4. Saddle Mtn Rider

    I love this post! What great photos and explanations. My first horse was a dun and my second horse was a buckskin. I thought they were the most beautiful horses in the world. One of our neighbors called my horse a “cayuse” and that pleased me a great deal. When i rode my dad’s old black pack horse, as a 7 year old, i was just sure that he looked just like The Black Stallion! Your horses are beautiful.

  5. Nice post! And serious dun factor!

  6. Tammy Wrensong Farm

    ummmmm, love those duns! especially those grullas! Thanks for a great post with photos to drool by. 🙂 You are so lucky to be surrounded by so many beautiful horses!

  7. Oooh thanks! I learned so much today!

    And by the way, if a Grulla is pronounced grew ‘ya, then my Llamas should be pronounced Yama! So, why does noone ever call them that? I even had one guy call my llamas ‘lama’ with the ‘a’ sounding like ‘pam’. Annoying!

    Your horses are gorgeous! And your photos are amazing. I loved the photos of the horses’ eyes.
    And the photo of the horse butt with ‘cellulite’. hahaha!

    You’re a hoot.

    So, inquiring minds want to know how much acreage your horse graze on. They look like they have free-range out there in that beautiful area. You are so blessed to live where you do 🙂

  8. Do you know if you have a red dun stallion what are the probable results of his foals when bred to palomino, buckskin, cremello, dunalino, etc.?

  9. tammy Schmaltz

    Could I e-mail you some picture and get your opinion if I have a dun horse ?

  10. Bruno Jaramillo

    May I use some of your pictures? I would use them for illustrating a book about horse’s colors.
    Bruno Jaramillo

  11. Very beautiful animals, I wish I could own my own one day, though I’d prefer to have a Friesian, but I love both the buckskin, and the dun colorings, thanks for showing the difference between the two!

    Btw, the wrinkles on the butt aren’t bad compared to the skinny horses around my town 😦

  12. A fantastic, fantastic site! Thank you so very much for the excellent explanation of dun colorings!!! Thank you!

  13. Your horses are stunning, and your article was very helpful, thank you. 🙂

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